MECHANICAL GAIN MEASUREMENT FOR A LANGEVIN VIBRATOR WHILE UNDER ELECTROMECHANICAL COUPLING

摘要

This paper will propose a new method to monitor the bouncing trajectory of a steel ball in order to determine the mechanical gain of a Langevin vibrator under electromechanical coupling. Rather than use a measurement of ultrasonic levitation force, this paper proposes an alternative. Using a steel ball, an elastic-bouncing tester is built to estimate the mechanical power of a Langevin vibrator operating near a resonant frequency. This will easily improve our understanding of the levitation phenomenon. The steel ball's bouncing height variation is measured by the proposed experiment system. It is much more apparent than the vibration amplitude of the vibrator. The characteristics of the electromechanical conversion between the flying trajectory of the steel ball and the mechanical output gain of the vibrator are modeled with a coefficient of elastic-bouncing, e_(dyn), by integrating the impact theory with the restitution coefficient. The measurement instrument, including the matrix photo-interrupters and a mixed signal oscilloscope, is developed to record the bouncing trajectory of the steel ball. This proposed measurement approach and related equations could be used as a practical and theoretical model to develop ultrasonic actuating transmission devices, or a new application in the future.